The development of a new all tantalum stopped flow microcalorimeter has proceeded to the point that a complete set of test data have been run the instrument is now operational. Experiments are in progress on a number of DNA drug binding reactions. This wok is being done in collaboration with scientists at Rutgers University. Only 80 microliters of each reagent are needed per reaction. The sensitivity is ten times that of the batch calorimeter requiring 1 ml of each reagent. For reactions with halflives faster than 0.1 second, a reaction can run every 3 minutes. The instrument is controlled by a microcomputer which takes the data and analyzes it on line. Extensive work with hemoglobin is planned for the coming year in collaboration with scientists at NIA, LAIR and Johns Hopkins University.